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Compsognathus longipes
Compsognathus (/kɒmpˈsɒɡnəθəs/;1 Greek kompsos/κομψός; "elegant", "refined" or "dainty", and gnathos/γνάθος; "jaw")2 is a genus of small, bipedal, carnivorous theropod dinosaur. Members of its single species Compsognathus longipes could grow to around the size of a turkey. They lived about 150 million years ago, during the Tithonian age of the late Jurassic period, in what is now Europe. Paleontologists have found two well-preserved fossils, one in Germany in the 1850s and the second in France more than a century later. Today, C. longipes is the only recognized species, although the larger specimen discovered in France in the 1970s was once thought to belong to a separate species and named C. corallestris. Many presentations still describe Compsognathus as "chicken-sized" dinosaurs because of the size of the German specimen, which is now believed to be a juvenile. Compsognathus longipes is one of the few dinosaur species whose diet is known with certainty: the remains of small, agile lizards are preserved in the bellies of both specimens. Teeth discovered in Portugal may be further fossil remains of the genus. Although not recognized as such at the time of its discovery, Compsognathus is the first theropod dinosaur known from a reasonably complete fossil skeleton. Until the 1990s, it was the smallest-known non-avialan dinosaur, with the preceding centuries incorrectly labelling them as the closest relative of Archaeopteryx. Compsognathus was the first dinosaur genus to be portrayed with feathers, by Thomas Henry Huxley in 1876. For decades, Compsognathus were famed as the smallest dinosaurs known; the first specimen collected was around 1 m (3 ft) in length. However, dinosaurs discovered later, such as Caenagnathasia, Microraptor and Parvicursor, were even smaller. The largest Compsognathus specimen is estimated to have weighed somewhere between 0.83 and 3.5 kg (1.8 and 7.7 lb).34 Compsognathus were small, bipedal animals with long hind legs and longer tails, which they used for balance during locomotion. The forelimbs were smaller than the hindlimbs and featured three digits equipped with solid claws suited for grasping prey. Their delicate skulls were narrow and long, with tapered snouts. The skull had five pairs of fenestrae (skull openings), the largest of which was for the orbit (eye socket),5 with the eyes being larger in proportion to the rest of the skull. The lower jaw was slender and had no mandibular fenestra, a hole in the side of the lower jawbone commonly seen in archosaurs. The teeth were small but sharp, suited for its diet of small vertebrates and possibly other small animals, such as insects. Its frontmost teeth (those on the premaxilla) were unserrated, unlike those further back in the jaw which were flattened and more strongly recurved.6 Scientists have used these dental characteristics to identify Compsognathus and its closest relatives.7 Reisdorf and Wuttke (2012) described the taphonomical phenomena of the German specimen of Compsognathus.8 The Compsognathus specimen discovered in Germany in the 19th century featured only two digits on each forelimb, leading scientists to conclude that this was how the creature appeared in life.9 However, the fossil discovered later in France revealed the manus (hands) to have had three digits,10 similar to other members of compsognathid genera. The fossilization of the German Compsognathus had simply failed to preserve the specimen's hands completely. Bidar supposed that the French specimen had webbed hands, which would look like flippers in life.11 In the 1975 book The Evolution and Ecology of the Dinosaurs, L. B. Halstead depicts the animal as an amphibious dinosaur capable of feeding on aquatic prey and swimming out of reach of larger predators.12 Ostrom debunked this hypothesis9 by showing conclusively that the French specimen was nearly identical to the German specimen in every aspect but its size. Peyer confirmed these conclusions.13 Category:Dinosaur